A truck box is a container that is mounted in the bed of a truck, typically a pick-up truck. Ordinarily, the truck box is mounted directly behind the cab of the truck and spans the distance between the side walls of the truck bed. Items like tools, fasteners, and the like can be stored in the truck box rather than simply laying loose in the truck bed.
A typical truck box has a rectangular receptacle and a lid that opens to permit access to the interior of the truck box. Many truck boxes have lateral portions, termed “tray pockets,” that overlie the walls of the truck bed to provide additional storage space. In some instances a biasing device, such as a spring or gas cylinder, is mounted within the interior of one or both tray pockets to facilitate opening of the lid.
As the lid of a truck box should remain closed while driving or when the truck is not in use, it is often desirable that the truck box include a locking system that secures the lid in a closed position. One such locking system is included with truck boxes sold under the trade name JOBOX® by Delta Consolidated Industries, Inc. (Jonesboro, Ark.). This locking system has two palm buttons located in the side walls of the box ends. Actuation of either of the palm buttons releases an internal lock and, assisted by gas cylinders located in the tray pockets, raises the lid to an open position. The internal lock includes an engagement member that is pivotally attached to a base bracket and a pawl member that is coupled to the push buttons with a connecting rod. The engagement member includes a slot that receives a striker pin attached to the lid and is spring-biased to a position in which it releases the pin. The pawl member is spring-biased to engage either of two recesses in the engagement member to prevent it from moving to the release position. Thus, when the lid is closed, the pawl member maintains the engagement member in a position to engage the pin. Actuation of the palm button disengages the pawl member such that the engagement member is urged by its spring to pivot sufficiently to release the pin. The lid is urged by the gas cylinder to move to a raised position. Closing the lid causes re-engagement of the pawl member and engagement member to retain the lid in place. In many truck boxes, two internal locks are included, and they are coupled such that both release when either of the palm buttons is actuated.
Although this type of lock has proven to be popular, there are some shortcomings. For example, positioning of the pin and engagement member are important, and slight misalignment, either horizontally or vertically, can prevent the lid from closing securely. This can be problematic due to varying manufacturing tolerances (typically a truck box is the full width of a pick-up truck bed, so a slight mismatch of components can become greatly exaggerated over the full length of the truck box), or if the lid becomes slightly misshapen due to abuse, racking, or the like. Also, the use of springs for both the engagement member and the pawl member can reduce consistency of operation, particularly when two internal lock units are used and the pins engage the engagement member at slightly different times.